SCHIZOPHRENIA : BIO EXPLA - Neural correlates of schizo Flashcards
we dont know exactly what causes schizo on a
biological level
we dont knwo excatly what casues schizo on a biological level however research has identified some
neural correlates
neural correlates i.e
brain structure or function
what is the best known neural correlate of schizo
neurotrnasmit - dopamine ( DA)
What is dopmaine important for
functioning of several brain systems related to symptoms of schizo
ORIGINAL DOPAMINE HYPOTHESIS - what was it based on
discovery that drugs used to treat schizo (antipsychotics which reduce DA ) caused symptoms similar to those in people with Parkinsons disease
a condition associated with low DA levels
ORIGINAL DOPAMINE HYPOTHESIS - from discovery drugs used to treat schixo patients casued symptoms similar ot those with Parkinsons - associated with low dopamine levels . Schizo might therefore be the result of
high levels of DA in subcortical areas of the brain
ORIGINAL DOPAMINE HYPOTHESIS - What does hyperdopaminergia mean
high levels of dopamine in brain
ORIGINAL DOPAMINE HYPOTHESIS - for example what can an excesss of DA receptors in pathways from subcortex of Broca’s area explain
specific symptoms of schizo such as speech poverty
and or
auditory hallucinations
ORIGINAL DOPAMINE HYPOTHESIS - broca’s area is responsible for
speech production
UPDATED VERSIONS OF DOPAMINE HYPOTHESIS - What did Davis et al propose
the addition of cortical hypodopaminergia
UPDATED VERSIONS OF DOPAMINE HYPOTHESIS - what does hypodopaminergia mean
abnormally low DA levels in the brains cortex
UPDATED VERSIONS OF DOPAMINE HYPOTHESIS - true or false hypodopaminergia can also explain symptoms of schizo
true
UPDATED VERSIONS OF DOPAMINE HYPOTHESIS - give example of how hypodopaminergia can cause symptoms of schizo
low DA in prefrontal cortex could explain cognitive problems e.g negative symptoms of schizo
UPDATED VERSIONS OF DOPAMINE HYPOTHESIS - also been suggested that cortical hypodominergia leads to
subcortical hypermanergia
UPDATED VERSIONS OF DOPAMINE HYPOTHESIS - as cortical hypominergia can lead to subcortical hyperdopaminergia what does this mean
both high and low levels of DA in different brain regions are a part of the updated version
UPDATED VERSIONS OF DOPAMINE HYPOTHESIS - explains link between
abnormal DA levels and symptoms
UPDATED VERSIONS OF DOPAMINE HYPOTHESIS - as well as explaining links between abnormal DA levels and symptoms what do current version of dop hypothesis try explain
the origins of abnormal DA functions
so what can we conclude overall about hyper/hypodopaminergia (Howes et al 2017)
both genetic variations ( family studies + candidate genes )
and early experiences of stress
both psychological and physical
make some people more senstive to cortical hypodopaminergia
and hence subcortical hyperdopaminergia
